/*
* Copyright (c) 2010-2012 Sonatype, Inc. All rights reserved.
*
* This program is licensed to you under the Apache License Version 2.0,
* and you may not use this file except in compliance with the Apache License Version 2.0.
* You may obtain a copy of the Apache License Version 2.0 at http://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the Apache License Version 2.0 is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
*/

package org.asynchttpclient.request.body;

import io.netty.buffer.ByteBuf;

import java.io.Closeable;
import java.io.IOException;

/**
 * A request body.
 */
public interface Body extends Closeable {

    enum BodyState {

        /**
         * There's something to read
         */
        CONTINUE,

        /**
         * There's nothing to read and input has to suspend
         */
        SUSPEND,

        /**
         * There's nothing to read and input has to stop
         */
        STOP
    }

    /**
     * Gets the length of the body.
     *
     * @return The length of the body in bytes, or negative if unknown.
     */
    long getContentLength();

    /**
     * Reads the next chunk of bytes from the body.
     *
     * @param target The buffer to store the chunk in, must not be {@code null}.
     * @return The non-negative number of bytes actually read or {@code -1} if the body has been read completely.
     * @throws IOException If the chunk could not be read.
     */
    BodyState transferTo(ByteBuf target) throws IOException;
}
